1. Field of the Invention
This invention relates broadly to methods for preventing or inhibiting the flow of water and other fluids, including oily water or toxic chemicals. In a preferred aspect, the invention relates to flood control systems, and more preferably to portable flood control systems.
2. Description of the Related Art
In a broad sense, flood control systems may be classified as either stationary or portable. One common type of stationary flood control system is a fixed, concrete dam. An early effort at improving stationary dams is disclosed in U.S. Pat. No. 1,077,791, disclosing a concrete dam structure having a "honeycomb" construction, with individual cells that may be either empty or filled with water.
For portable flood control, the most well-known and widely used technique is still conventional sandbags. During flooding, sandbags are typically placed by human hands at locations that are still above the rising water level, to collectively create a wall, dam, or barrier against the flood waters. Sandbags, however, have a number of problems. One of the problems with sandbags lies in the amount of human labor required for their installation. Each bag must be filled, usually by hand, then placed at the location where the barrier is being constructed. Another problem is the need for sufficient quantities of sand for filling purposes. It is of course preferred that the sand be close to the location where the barrier or dam is being constructed. When that is not the case, the necessary quantities of sand must be transported, which is expensive and time-consuming. Yet another problem is the logistics of coordinating the human effort of transporting the sand, filling the bags and placing the bags at the right location within the appropriate time frame. The sheer number of sandbags often makes this a Herculean task, which is exacerbated by the fact that it is often done in pouring rain. Still another problem is that after flooding, once the waters have subsided, the sandbags must be removed, either in a filled condition, or else emptied of their contents at the location. Consequently, other approaches have been suggested as a substitute for sandbags. For the most part, however, as far as the inventors know, these systems have not been used commercially, at least not to any appreciable extent.
Many of these systems simply rely on water or fluid (instead of sand) placed inside tubes or other structures to provide the weight needed to resist the hydrostatic forces of rising water. Such systems are exemplified in the "Water-Bag Dam or Dike and Method," disclosed in Jackson III, U.S. Pat. No. 4,692,060; in the "Barrier for Containing Floods," disclosed in Coffey, U.S. Pat. No. 4,921,373; in the "Wall-Like Retainer Segments for Retaining Fluids," disclosed in Baker, U.S. Pat. No. 5,632,5723; in the "Device for Controlling Flood Waters and/or Hazardous Liquid Spills," disclosed in Hendrix, U.S. Pat. No. 5,040,919; and in the "Apparatus and a Method for Joining Water Structure Sections or the Like," disclosed in Doolaege, U.S. Pat. No. 5,059,065. Some systems are rather complex. For example in Jenkins, U.S. Pat. No. 5,645,373, the "Flood Control Barrier System and Method" involves a complicated system of elongated, inflatable tubular ballast members. At least one of the shortcomings of the above systems is that they are difficult to install quickly. Further, they are incapable of providing resistance to flood waters unless they are filled with water.
Some systems rely on the use of individual "water bags" or other plastic, flexible water-filled articles of various sizes. These water bags serve essentially as replacements for sandbags. These are exemplified by the "Flood Disaster Control Bag," in Wagner et al., U.S. Pat. No. 4,362,433; the "Water Filled Plastic Dam Structure," in Serota, U.S. Pat. No. 3,213,628; the "Hovering Bag Breakwater," in Weigel et al., U.S. Pat. No. 3,191,386; and the "Method and Apparatus for Constructing Hydraulic Dams and the Like," in U.S. Pat. No. 5,125,767. Among the many shortcomings of these "water bag" approaches is that many of them simply do not adequately overcome the time and labor problems presented by sandbags. For example, the water bags or containers in Wagner '433 and Serota '628 must be filled with water before they can provide an effective barrier to flood waters. The plastic container in Serota '628 must be filled with water even before it is positioned, since without water, in its collapsed state, it is essentially formless. Unless these containers are filled with water, they cannot be stacked nor can they even form an effective barrier.
Accordingly, as discussed in greater detail below, the present invention provides a much improved approach to flood control, overcoming one or more of the above shortcomings of earlier systems.